Study On The Preparation Of Iron-Based Structural Material Using Hyperpure Powders And Treatment Of Carburization

This research was mainly on the structural material of powder metallurgy which was prepared by JHY100.27 hyperpure iron powders. There were two different methods adopted by both alloying addition agent and carburizing treatment to improve the property of iron powder sintered material, enlarge the application of hyperpure iron powders and develop new products. Through the experiment we got the required alloying ingredients. Also we analysed the mechanical property and microstructure of powder metallurgical material. To supply the necessary reference data for the preparation of iron-base alloy material using hyperpure iron powders.The experiment adopted the traditional powder metallurgy, including composition design, moulding, and sintering. The densification plays a key role in improving mechanical property of sintered body. Under the provided condition of experiment, the pressure was chosen as 800MPa and 900MPa. The density of iron-base alloy material can reach 7.010g/cm3 under 900MPa. Adding carbonaceous, cupreous and the alloyed element to the hyperpure iron powder step by step to improve the property of material. Here is the result:when the carbon increased from 0.6% to 0.9%, the hardness and the stretch intensity was also in hoist trend; instant liquid—phase sintering was taken place after the accession of 2%Cu to increase the density, intensify the ferrite and improve the diffusivity of alloyed element then in order to make the microstructure equality. It made the tensile attain 469.84MPa, which was enhanced by 0.5times more. The density and the hardness were also heightened. The MnCrMo were mainly acceded by prior alloyed powder, over-all the properties reach the best after the FY-1 alloyed addition got 2%. The toughness was 18.47J/cm2, the tensile was 574.84MPa, the hardness was HRC28.33, density was 7.096 g/cm3 under 800MPa; the impact toughness was 20.06J/cm2, the tensile was 597.63MPa, hardness was HRC36.7, density was 7.099g/cm3 under 900MPa. The extend intensity was enhanced by 30%, while the hardness was increased by 1.3times.On the other side, solid carburization treatment was proceed to the hyperpure iron structural material which was only maintained carbon under temperature 1010℃. Through the different medium of time, it got different depths of penetration. It would be 2mm after 6hours and the hardness of surface could attain the same affect as alloyed addition. With the prolonging of carburizing time, superior pearlitic structure could be gotten, the over-all properties of material was advanced, which would make a well foundation of more heat treatment.